1. Field of the Invention
The present invention relates to a numeral display device wherein individual segments arranged to comprise each numeral may be selectively lightened, darkened, or changed in color from the surrounding background in order to make the desired numeral visible. In particular, the present invention relates to a numeral display device having self-storing segments.
2. Prior Art
The system of seven segment numerals has heretofore been widely used, both with manually changeable segments and with liquid crystal displays. The individual segments are lightened or darkened depending on the desired numeral to be formed from 0 to 9. Liquid crystal displays have been found to be adequate for small devices viewed at short distances but are difficult to see in large devices viewed at longer distances.
The present invention is not constrained to small displays and may readily be adapted to large highway signs. Additionally, the present invention provides a display device that may be remotely controlled.
Applicant has conducted a patent search and is aware of the following U.S. patents:
______________________________________ U.S. PAT. NO. PATENTEE ISSUE DATE ______________________________________ 2,439,553 Winn April 13, 1948 3,200,525 Francis August 17, 1965 3,582,907 Taylor June 1, 1971 3,521,946 Wrench July 28, 1970 2,986,982 Kaprelian June 6, 1961 2,433,456 Jansen December 3, 1947 2,489,751 Chandler November 29, 1949 4,796,370 Chang January 10, 1989 4,164,824 Nidelkoff August 21, 1979 3,273,270 Skrobish Sept. 20, 1966 4,777,747 Murray, Jr October 18, 1988 4,627,182 Weiss December 9, 1986 4,539,768 Halliday Sept. 10, 1985 3,764,200 Glattli October 9, 1973 3,814,506 Steele June 4, 1974 3,789,525 Bogg February 5, 1974 4,220,948 Trame September 2, 1980 4,024,532 Sherwin May 17, 1977 ______________________________________
Kaprelian (U.S. Pat. No. 2,986,982) discloses a pair of spaced glass plates. A center opening is connected by a tube to a pump in order to move opaque fluid from a tank. In the normal pumping condition, light cannot pass through the fluid. To open, the pump sends air through the tube which fills the space and allows light to pass therethrough.
Sherwin (U.S. Pat. No. 4,796,370) discloses a multi-element display wherein each element may be reversibly rotated about a mounting rod by an electric motor.
Nidelkoff (U.S. Pat. No. 4,164,824) illustrates one of the problems overcome in the present invention. A self-storing display allows each shutter to be received in a linear pocket so that it may be manually slid to a retracted position where the back plate is revealed. When the shutter is retracted, there must be sufficient space behind the background face to accomodate it.
Skrobisch (U.S. Pat. No. 3,273,270) discloses a segmented display wherein each segment is longitudinally divided and pivots to fold together to conceal its face. A linear actuator is shown in FIGS. 20 and 21 having a pinion gear that meshes with a rack.
Murray (U.S. Pat. No. 4,777,747) provides each segment of a seven segment display with a guide rim or flange overlapping edge to slidably receive an element that may be manually inserted or removed.
Weiss (U.S. Pat. No. 4,627,182) provides a two sided display element that may be rotated by the force of voltage applied to a crystal.
Halliday (U.S. Pat. No. 4,539,768) shows a seven segment display with a flap for each segment that may be manually pivoted to cover or uncover with assistance of spring-loaded pivots.
Chang (U.S. Pat. No. 4,796,370) shows a seven segment display wherein each segment has a transverse axle that may be rotated by a small electric motor.
Glattli (U.S. Pat. No. 3,764,200) discloses a cylindrical reflecting surface with an axially extending slot that has a flat planar element movable up or down to make the surface appear illuminated.
Steele (U.S. Pat. No. 3,814,506) provides panels having a pair of outer sheets with a third, center sheet slidably sandwiched therebetween. The center sheet is movable by a cam and lever mechanism.
Bugg (U.S. Pat. No. 3,789,525) discloses a pair of resilient film loops wherein one end of each loop is fixed in contiguous relation to a movable frame so that the film loops may be brought into and out of a visible position.
Trame (U.S. Pat. No. 4,220,948) provides a sliding shutter between front and back plates with a tab extending through an opening to manually slide the shutter.
Accordingly, it is an object and purpose of the present invention to provide a numeral display device which is compact in design and wherein its individual segments are self-storing and easily changeable.